(1) Field of the Invention
The present invention relates generally to sonobuoys and more particularly to a water-activated sonobuoy system.
(2) Description of the Prior Art
An active sonobuoy is one that transmits an acoustic signal into the surrounding water environment. Typically, it is desirable to produce a plurality of acoustic signals over a period of time. To do so, state-of-the-art active sonobuoys contain an array of active transducers which are driven electronically by means of a signal generator, a power source and an electronic driver stage. The power source, i.e., a battery, provides the power to operate the signal generator and the electronic driver. The signal generator produces a signal of a prescribed configuration that is amplified at the driver stage to drive the array of active transducers. Each active transducer produces an acoustic signal that is propagated into the water. The duration and period of repetition of the acoustic signal is determined by the signal generator. The disadvantages of these electronically driven active sonobuoy systems include their complexity, cost and reliability in hostile environments.
Unfortunately, replacing the array of active electronics transducers with simple (mechanical or explosive) sound sources brings about another set of obstacles. Namely, since these simple sound sources can only generate a "single" (ping or explosion) acoustic signal, it is necessary to provide means for controlling the deployment of a plurality of the sound sources over a period of time.